cl = 0.05;
Point(1) = {0, 0, 0, cl};
Point(2) = {3, 0, 0, cl};
Point(3) = {3, 0.1, 0, cl};
Point(4) = {0, 0.1, 0, cl};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 1};
Line Loop(6) = {3, 4, 1, 2};
Plane Surface(6) = {6};
Physical Line(8) = {4};
Physical Line(9) = {2};
Physical Surface(7) = {6};
Physical Line(10) = {3};
